461 research outputs found
Low regularity solutions of two fifth-order KdV type equations
The Kawahara and modified Kawahara equations are fifth-order KdV type
equations and have been derived to model many physical phenomena such as
gravity-capillary waves and magneto-sound propagation in plasmas. This paper
establishes the local well-posedness of the initial-value problem for Kawahara
equation in with and the local well-posedness
for the modified Kawahara equation in with .
To prove these results, we derive a fundamental estimate on dyadic blocks for
the Kawahara equation through the multiplier norm method of Tao
\cite{Tao2001} and use this to obtain new bilinear and trilinear estimates in
suitable Bourgain spaces.Comment: 17page
Uncertainty Principle of Morgan type and Schr\"odinger Evolutions
We prove unique continuation properties for solutions of evolution
Schr\"odinger equation with time dependent potentials. In the case of the free
solution these correspond to uncertainly principles referred to as being of
Morgan type. As an application of our method we also obtain results concerning
the possible concentration profiles of solutions of semi-linear Schr\"odinger
equations
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